Today, I held a house party. For fun, I made sure all the beer was alcohol-free, so I could see which of my friends would be weak-minded enough to end up acting drunk. Three did. I was one of them. FML

OP you threw a 'house party' without drinks. Thats pretty much an oxymoron, and its very stupid, lame and weird thing to do. What the hell did all the people do all night? Must have been awkward as fuck. Did you lose friends?

Guys it's called the placebo effect, u trick or give something to someone who thinks that it will have an affect on them. The mind does the rest, believing the problem was solved eg some pain can be cured by placebo, also this situation is a great example

Got some biomedical uses, they usually give placebo injection to one group of mice (usually just a saline solution) and the potential cure to another group, they then record the results to def if the vaccine/medicine is effective

Obviously OP forgot. It's not that bizarre, especially if it was a longer night (more likely to forget as party goes on) or something that OP does regularly (easier to slip into a familiar routine). So yes, still placebo effect.

I hate this phrase so much.. It's way overused and complete bullshit. If everyone thought this way, then absolutely nothing would get done in this world. Not trying to pick on anyone, I just hate that god damn phrase with a passion.